Actress Phylicia Rashad is joining the cast of "Empire" season 3 as Diana Dubois, while actor Morocco Omari who plays Tariq Cousins, was promoted to series regular.

Diana is described as the wealthy mother of Angelo, a character that will be played by actor Taye Diggs. Rashad is best known for playing Clair Huxtable on the long-running sitcom "The Cosby Show." She played a devoted mother, lawyer, and feminist on the show and her character was loved by the viewers.

While she played an ideal mother on the sitcom, Rahsad's Diana will be quite the opposite. Angelo is set to be Cookie Lyon's (Taraji P. Henson) new love interest. Additionally, Angelo is described as a Harvard law graduate who chose community service over private practice. Diana is ambitious and is determined to see her son on higher office. Her meddlesome ways could create more conflict and trouble for the Lyons.

Meanwhile, viewers of the show have already met Omari's character in the last three episodes of "Empire" season 2. Tariq first appeared as an FBI agent who seemed to be after Lucious Lyon (Terrence Howard) and his company, Empire Entertainment. It was later on revealed that his association with the Lyons goes deeper than that. He and Cookie shared a past growing up in Philadelphia. And one of the biggest twists in the finale is the revelation that he is actually the son of Lucious' father, making them half-brothers.

"Empire" is known to guest big stars aside from telling a compelling story about fame and family. Some stars confirmed to make an appearance of season 3 are superstars Kid Cudi, French Montana, Mariah Carey, Sierra McClain, and Xzibit.

"Empire" season 3 returns to the small screen on Sept. 21 at 9 p.m. on FOX.